The difference with this situation is that the responsible parties still exist while we're aware of the problem. They are who should be paying for the complete

The difference with this situation is that the responsible parties still exist while we're aware of the problem. They are who should be paying for the complete cost of cleanup, remediation, and damages to bystanders and property. Letting them slip out of the full liability with token or estimated damages, resume fraudulently transferring profits to shareholders, and putting the site in the back of the publicly funded queue is exactly what we don't want to happen. It's a terrible dynamic to rely on post-facto financial enforcement on business people that are mentally incapable of understanding what they've done wrong (as opposed to say proactive regulation that would have prevented this entirely preventable derailment, and separately prevented the deliberate chemical release), but it's all we've got right now.